This invention relates in general to mining and in particular to a new and useful device for extending supply lines to winning machines in mining operations.
The invention concerns an energy supply unit for winning machines pulled by a traction mechanism in mining operations, where the winning machine is pulled back and forth on the longwall conveyor along the head end, the supply lines are stored at the ends of the working face and deposited on the traction mechanism in a housing secured on the longwall conveyor, with supporting bars for depositing the supply lines secured symmetrically or asymmetrically on the traction mechanism of the winning machine, these supporting bars forming a right angle with the axis of the traction mechanism, and where furthermore several supply lines are deposited in juxtaposition or superposition on the supporting bars.
A mineral extraction machine which is drawn across the longwall at a coal face is, as a rule, guided on a work face conveyor. Drive for the machine is effected through traction means driven from the work face side of the conveyor. The required drive and operating means are supplied to the extraction machine by means of lines either in the form of loops by a cable trolley, with deflecting rollers, guided in a cable channel arranged in the work face conveyor or dragged by the extraction machine itself in a cable channel, possibly with the use of a cable chain. At higher propulsion speeds of the extraction machine, these feed arrangements causes difficulties. Jerky loadings occur, which lead to pronounced lateral and/or vertical deflection of the lines. The overall height of the cable channels therefore become unacceptable for low longwalls. Also the risk of fatigue fractures increase through frequent bending of the lines below the minimum bending radius, especially with low work faces. In the case of drag lines, a relatively high resistance to movement of the lines sliding on the stationary base also appears and contributes to a reduction in the life of these lines. Cable chains, moreover, produce an appreciable noise nuisance in mine workings.
In German Pat. No. 1,247,995 it is proposed to deposit the supply lines on the traction means of the extraction machine. In that case, and according to German Pat. No. 1,242,541, the lines are stored on or dispensed by drums positioned in head drifts or tunnels connected to the longwall. Although the lines are in this case largely relieved of tension forces, they are pressed against the ceiling and wall of a guide channel which is closed at the top, when the lines are traveling through troughs and are being unreeled in the case where a tautly tensioned drag chain is used. This means increased line wear through abrasion and damage of the lines through squeezing. The tractive or load run of the traction means slides on the floor and thereby increases the resistance to movement. Moreover, only one supply line at a time can be deposited in the guide channel on the traction means away from the extraction machine in both work face directions. In addition, electrical lines cannot be pushed within the guide channel for reasons of safety against firedamp. Accordingly, the cable must be guided out through a slot, which is not possible in the case of the equipment of German Pat. No. 1,242,541, because the clear width of the slot is smaller than the diameter of the energy supply line.